Radiofrequency (RF) electrode catheters have been in common use in medical practice for many years. They are used to stimulate and map electrical activity in the heart and to ablate sites of aberrant electrical activity. Specifically, targeted ablation may be performed for a number of indications. For example, ablation of myocardial tissue is well known as a treatment for cardiac arrhythmias by using a catheter to apply RF energy and create a lesion to break arrhythmogenic current paths in the cardiac tissue. As another example, a renal ablation procedure may involve the insertion of a single or multi-electrode catheter into a renal artery in order to complete a helical or circumferential lesion in the artery in order to denervate the artery for the treatment of hypertension. In other uses, the electrode catheter is inserted into a patient and positioned in a chamber of the heart to determine the location of aberrant electrical activity.
In many instances, the use of a multi-electrode catheter is preferred. Further, catheters are increasingly called upon to perform multiple functions, whether it is diagnostic or therapeutic. Often the catheters serve both functions. The size of the catheter is also a concern. In many instances, a radial insertion point into the patient is preferred over a femoral approach. Also, smaller is usually considered less invasive and less traumatic along the insertion pathway. Therefore, in designing multi-electrode catheters, internal lumen space is at a premium. The lumens may, among other things, house all of the wiring used to connect the electrodes and various sensors to the system controller, as well as function as a conduit for supplying irrigation fluid to the treatment site. Each of these functions that a single catheter performs further increases the demand for space within the lumen.
Accordingly, it would be desirable to provide a multi-electrode catheter that can accommodate more features while maintaining a desirable insertion size. As will be described in the following materials, this disclosure satisfies these and other needs.